Biological Foundations 112, Lecture 33


Monocots

Chapter 27
Five Kingdoms-5 12:24-16:33


I.   Division Anthophyta

     A.   Called angiosperms because the ovule develops inside an enclosed ovary

     B.   Contains all true plant parts:  roots, stems, leaves, flowers, fruits, and seeds

     C.   The gametophyte is dependent on the sporophyte for all phases of its formation and        
           development

     D.   Comparison of monocots and dicots

            1.   Monocots

                  a.   Flower parts in 3s or multiples of 3s

                  b.   Leaves with parallel veins

                  c.   One cotyledon per seed

                  d.   Stems with scattered bundles

                  e.   Roots, in primary growth, contain a vascular cylinder with six to many                
                        protoxylem poles

            2.   Dicots

                  a.   Flower parts in 4s or 5s or multiples of 4s or 5s

                  b.   Leaves with net veins

                  c.   Two cotyledons per seed

                  d.   Stems with vascular bundles in a ring

                  e.   Roots, in primary growth, contain a vascular cylinder with two to five protoxylem
                        poles

II. Class Monocotyledonae

    A.   Two types of monocots have been included for your study, the monocots with flowers    
           that are showy and that you are accustomed to seeing and monocots that have                
           grass-like flowers which are not showy.

    B.   Showy flowered group

           1.   Key characteristics

                 a.   Superior/inferior ovaries

                 b.   Regular/irregular flowers

           2.   Genera

                 a.   Family Liliaceae - lily family

                       (1)  Ovary superior

                       (2)  Flowers regular

                 b.   Family Iridaceae - iris family

                       (1)  Ovary inferior

                       (2)  Flowers regular

                 c.   Family Orchidaceae - orchid family

                       (1)  Ovary inferior

                       (2)  Flowers irregular

    C.   Grass-flowered group

           1.   Key characteristics

                         Sedges have edges

                              Rushes are round

                         Grasses have nodes

                              That are easily found

           2.   Genera

                 a.   Family Cyperaceae - sedge family

                       (1)  Triangluar stems

                       (2)  No visible nodes

                       (3)  Typically found in damp habitats

                 b.   Family Juncaceae - rush family

                       (1)  Round stems

                       (2)  No visible nodes

                       (3)  Typically found in wet habitats

                 c.   Family Poaceae - grass family

                       (1)  Round stems

                       (2)  Visible nodes

                       (3)  May be found in wet, damp, or dry habitats


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